In the railroad industry, one of the more difficult and labor intensive operations is the laying of track, either in new railway construction or in the replacement of worn or damaged existing rails. It is an industry standard for rails to be manufactured in sections that are each 39 feet long. In order the maximize quality control and minimize costs, the sections are often welded together end to end at a steel mill to form longer sections that are commonly known as ribbon rails. These ribbon rails can be any length up to 1800 feet long or even longer.
Ribbon rails are transported to the area along the railway where they are to be installed by loading them onto rail cars that are equipped with special bunks on which the ribbon rails are carried side by side. There are typically a number of tiers provided on the bunks with each tier holding eight to ten rails spaced apart transversely. Due to their extensive lengths, the ribbon rails span the bunks on a number of different rail cars which are driven by a locomotive along the track to the area where the rails are to be installed.
Conventional practice for unloading the ribbon rails on each side has involved the use of a winch. A winch cable is extended from the winch drum by hand and passed manually through a number of thread boxes and around pulleys and sheaves and is then connected to the end of the first rail that is to be unloaded. The winch is operated to pull the rail off of the back end of the rear rail car and onto the railway bed. The end of the first rail is then anchored to the ground. The rail that is beside the first rail is then pulled off by the winch until its end can be anchored to the ground beside the first rail. The train is driven forwardly at this point to unload the first two rails.
Next, the second pair of rails are winched off until their back ends can be connected to the front ends of the first pair of rails by rigid tie bars. As the train is moved forwardly again, the second pair of rails is unloaded and is situated end to end with the rails in the first pair. The remaining rails are thereafter unloaded successively in this fashion.
As can easily be appreciated, this procedure requires a considerable amount of manual labor. Workers must thread the winch cable through the boxes and the sheave system repeatedly and manually connect and disconnect the cable and the tie bars. The workers also have to cover great distances to detach the tie bars each time a pair of rails has been unloaded. Perhaps even more disadvantageous than the labor costs is the risk of serious injury that is encountered due to the need for extensive manual handling of the rails, the winch cable, the tie bars and other associated equipment.
U.S. Pat. No. 5,762,464 to Hertilendi discloses railway equipment using a crane and guide rollers through which rails can be fed to load them from a ditch onto a rail car. The guide rollers do not provide power assistance for either loading or unloading of rails, and the crane is used to perform essentially the same work as the winch which is used in the conventional unloading procedure previously described. Consequently, if this type of equipment is used in the unloading of rails, the rails still have to be tied end to end manually using tie bars, and the high labor costs and the high risk of personal injury remain serious problems.